The present invention relates to a method and composition for preventing the ingrowth of intraocular tissue, and in particular discloses means for preventing growth of lens fiber cells and fibroblast-type cells in a lens capsule after surgical removal of the lens.
Surgical removal of the lens from the lens capsule and insertion of an intraocular lens is commonly indicated as treatment for cataracts. In this procedure, complete removal or destruction of all lens cells and epithelial cells in the lens capsule is imperative if complications are to be avoided. One of the most common complications of this type is ingrowth of lens cells or other cells in the lens capsule following intraocular lens implantation.
"Secondary cataract" formation is a proliferation of cells occurring within the year following surgery in approximately 17--30% of patients receiving intraocular lenses. In subsequent years, the percentage of patients experiencing such ingrowth increases.
The secondary cataract formation generally results from the migration of lens epithelial cells into the posterior capsule with the proliferation of cortical material (Elschnig pearls). Any cellular proliferation in the lens capsule is to be avoided if secondary cataract formation is to be prevented. Every effort is made, of course, during the phacoemulsification or extracapsular with aspiration and irrigation procedure utilized to remove the natural lens, to completely remove all lens cells, lens fiber cells, and/or epithelial cells that may subsequently proliferate and form secondary cataracts. However, these efforts, to date, have not been entirely successful, due primarily to the fragmentation of the lens tissue during surgical removal and the difficulty of removing every lensrelated cell.
Extracapsular cataract extraction and implantation of intraocular lenses are being performed at ever increasing rates in the United States. Well over 1 million such procedures are performed every year, and as the retirementage population increases, the incidence of such procedure is also expected to increase.
Accordingly, there is a great need for an effective and simple procedure for ensuring the complete removal and/or destruction of lens cells and other proliferative cells from the lens capsule prior to implantation of the intraocular lens.